This section is intended to provide a background or context to the invention that is recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived, implemented or described. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section.
The following abbreviations that may be found in the specification and/or the drawing figures are defined as follows:
BAW bulk acoustic wave
BB baseband
BiCMOS bipolar CMOS
CDMA code divisional multiple access
CMOS complimentary metal-oxide semiconductor
F frequency
I/O inputs/outputs
IC integrated circuit
LNA low noise amplifier
LO local oscillator (signal)
PA power amplifier
PWB printed wiring board
RF radio frequency
RFIC radio frequency integrated circuits
S21 s-parameter transfer function from input port to output port
SAW surface acoustic wave
TIF transfer impedance filter
WCDMA wideband CDMA
Z impedance
Signals that enter or leave active or passive components of a transceiver may be filtered in order to remove unwanted (e.g., interfering) signal components. More bands the transceiver covers, more band selection filters are needed.
The RF receivers may tolerate high blocking signals while maintaining their own performance. This may require filtering for RF-signals prior to a LNA (low noise amplifier) and in many systems also after the LNA. This may especially be true in code division multiple access systems (e.g., CDMA2000 and WCDMA) where a transmitter may send its high-level signal while a receiver receives a very low-level signal.